Advertisements
Advertisements
प्रश्न
Find the sum of first 16 terms of the A.P. whose nth term is given by an = 5n – 3.
Advertisements
उत्तर
Given, nth term of A.P. is an = 5n – 3
∴ a1 = 5(1) – 3 = 2
And a2 = 5(2) – 3 = 7
∴ Common difference, d = 7 – 2 = 5
∴ Sum of n terms of A.P., Sn = `n/2[2a + (n - 1)d]`
∴ S16 = `16/2 [2(2) + (16 - 1)5]`
= 8(4 + 75)
= 8 × 79
= 632
संबंधित प्रश्न
If the ratio of the sum of first n terms of two A.P’s is (7n +1): (4n + 27), find the ratio of their mth terms.
Find the sum of the following APs.
0.6, 1.7, 2.8, …….., to 100 terms.
In an A.P., if the first term is 22, the common difference is −4 and the sum to n terms is 64, find n.
Find the sum of two middle most terms of the AP `-4/3, -1 (-2)/3,..., 4 1/3.`
Find an AP whose 4th term is 9 and the sum of its 6th and 13th terms is 40.
Find the A.P. whose fourth term is 9 and the sum of its sixth term and thirteenth term is 40.
The number of terms of the A.P. 3, 7, 11, 15, ... to be taken so that the sum is 406 is
If the first term of an A.P. is a and nth term is b, then its common difference is
If the second term and the fourth term of an A.P. are 12 and 20 respectively, then find the sum of first 25 terms:
Find the sum of the first 10 multiples of 6.
